Sheave



Dec. 2, 1941. F. v.v LARSEN SHEAVE Filed Aug. 3, 1940 l Figure 3 is a detail plan Patented Dec. z, 1941 SHEAVE Paul V. Larsen, Chicago, Ill.. assignor to Pettibonedgiullikcn Corporation, a corporation of Application August 3, 1940, Serial No. 351,032

This invention relatesv in general to rotatable members, such as sheaves, and more particularly to a novel method and means for statically balancing the same.

A principal object of the invention is the provision on a sheave, or other rotatable member, of a plurality of circumferentially spaced apertures or pockets which are designed to selectively receive molten metal in the quantity or amounts necessary for accurately balancing the member, and which are also designed to completely eliminate the possibility of such metal loosening or coming out after it has hardened and when the member is in motion.

Another important object of the invention is the provision of such pockets with radially disposed walls which are undercut or dove-tailed at two or more points so as to function in the desired manner regardless of the amount of molten metal which is deposited therein.

A further important object of the invention is the provision of such pockets with circumierentially spaced and axially extending ribs on the side walls thereof to prevent longitudinal moving or slippage of the metal deposited therein.`

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, when taken in connection .with the accompanying drawing, discloses a preferred embodiment thereof.v

Inthedrawingr Figure l is an elevationalviewot a sheave embodying the features vof the inventiom' Figure 2- is a detail, radial section taken through one Vof the balancing pockets substantially on the line 2--2 of Fig. 1; Y

balancing pockets; and

.Figure 4 is va longitudinal .section taken-sub-- stantiallyon the line l-l of Fig. 3, j I Referring more-particularly to the drawing, reference numeral II indicates in general a sheave of any suitable or desired construction,

' which isemployed herein merely as illustrating one of any number-of diierent types of rotatable members with which the instant invention may be employed. The sheave II comprises an exteriorly slotted rim l2, and a plurality of circumferentlally spaced spokes I3V and a hub portion I l which are preferably formed integrally therewith.

'Ihe inner portion of the rim I2 is provided intermediate each pair of adjacent spokes I3 with a radially or outwardly and circumferenview of one of the vupper or -inner openend-of the pocket, .slopes tially or longitudinally extending recess or balancing pocket, indicated generally by reference numeral IS. The same number of pockets I5 are thus provided as there are spokes I 3, and they are equally spaced from each other circumferentially of the sheave in the manner illustrated in Fig. 1.

Referring more particularly to Figs. 2 to 4, it will be seen that each of .the balancing pockets I5 comprises longitudinally extending or side walls which are undercut or dove-tailed at I 6 and are also undercut at the base of the pocket at I'l, these undercut portions joining on each side wall to denne a longitudinally disposed rib I8 which is spaced a short distance from the bottom ot the pocket and projects laterally into the same. Each of the side walls ofthe pocket I5 is also provided with laterally projecting, spaced ribs I9 which intersect or cross each other, as

shown in Fig. 4, to form a beaded lattice-work. 'I'hese ribs I9 are arranged on each side wall in two parallel series inthe main part of the pocket as deilned by the undercut portions i6, the ribs of one series being disposed at right angles to those of the other series. Adjacent the longitudinal rib I8, adjacent ribs I9 of the two diierentf' series intersect and terminate in downwardly or undercut portion I1. Each of the end walls of each pocket I5' is undercut at 22 adjacent the from such undercut portion toward the center of the pocket, and is undercut 'again at ZI-below or outwardly of the ribs I8.

fAs has been stated hereinbefore, the purpo ofthe` several-pocketsl I5 is to vfacilitate the ac curate balancing of the sheave II, or any other rotatable member in which they may be provided. To accomplish thisfunction, the sheave Ii is freely rotatably mounted yupon'a suitable shaft, or the like, to determine its condition of static balance, and molten metal,- preferably lead, -is selectively poured into one or more of the pockets I5 in such amount or quantities as will eiect'perfect static balance of the sheave.

'I'he necessary amount oifv molten metal thus poured into any one of the pockets I5 may vary between relatively. wide limits in any given case. The provision of the undercut portions i8, I1, 22 and 23 and the ribs I8, I9 and 2| in each balancing pocket I5, however. will positively prevent such metal from loosening, slipping or coming out of the pockets, after it h'as hardened, regardless of the particular amount thereof which has been added. This desired result will obtain even if the amount of lead, for example, which is poured into a balancing pocket l5 does not exceed 1/2 ounce in weight, and without regard to the quantum of the forces subsequently exerted thereon by the rotation of the sheave, or other rotatable member. Th'e importance of so preventing shifting or other movement of the added metal relative to the rotatable member may best be realized, perhaps, when it is considered that any such shifting of the metal would result in the rotatable member immediately being thrown out ofrbalance.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts with'- out departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A rotatable member having a plurality of similar pockets formed therein and equally spaced from each other circumferentially of said member to selectively receive molten metal in an amount necessary to statically balance the member, the walls of each of said pockets having under-cut portions and the side walls thereof having longitudinally spaced, angularly disposed ribs extending transversely into said pockets, whereby after any amount of said molten metal has solidified it will positively be prevented from any movement relative to said member upon rotation thereof.

2. A sheave, comprising a rim portion, a plurality of pockets formed in the irmer surface of said rim portion and equally yspaced from each other circumferentially thereof, said pockets having under-cut portions and a beaded latticework formed on some of the walls thereof, and metal inserts selectively cast in said pockets in an amount necessary to balance said sheave, said under-cut portions and beaded lattice-work preventing displacement of said inserts relative to said rim portion upon rotation of said sheave.

3. A rotatable member having a rim portion, a plurality of similar pockets formed in the inner surface of said rim portion and equally spaced from each other circumferentially of said portion to receive molten metal selectively in any amount necessary to balance the member statically, the walls of each of said pockets being ldove-tailed in two directions, the side walls in each of said pockets having spaced ribs extending laterally into the pockets whereby shifting relative to said member of any amount of metal placed therein, after the same has hardened, is prevented.

4. A sheave, comprising a rim portion, a plurality of pockets formed in the inner surface of said rim portion and equally spaced from each other circumferentially thereof, each of said pockets having a plurality of under-cut portions in each direction, andl a beaded lattice-work formed on some of the walls thereof, and metal inserts selectively cast in said pockets in an amount necessary to balance said sheave. said under-cut portions and beaded lattice-work preventing displacement of said inserts relative to said rim portion upon rotation of said sheaveI regardless of the size of said inserts.

5. A sheave, comprising a rim portion, a plurality of elongated pockets formed in the inner surface of said rim portion and equally spaced from each other circumferentially thereof, each of said pockets having a. plurality of under-cut portions along each of the side walls of said pockets and -at each end thereof to form continuous ridges extending inwardly from the walls of said pockets, a beaded lattice-Work formed on the side walls of each of the pockets and disposed at angles to said ridges, the spaces between the ridges and the lattice-work forming holding depressions, whereby after molten metal placed in said pockets to balance the sheave statically has solidified it will be positively prevented from any movement relative to said member upon rotation thereof regardless of the amount of molten metal required.

6. A sheave, comprising a rim portion, a plurality of elongated pockets formed in the inner surface of said rim portion and equally spaced from each other circumferentially thereof, each of said pockets having a plurality of under-cut*V portions, along each of the side walls of said pockets and at each end thereof to form Continous ridges extending inwardly from the walls of said pockets, said ridges being parallel to each other and to the inner surface of the rim portion, a beaded lattice-work formed on the side walls of each of the pockets and disposed at angles to said ridges, the spaces between the ridges and the lattice-work forming holding depressions, whereby after molten metal placed in said pockets to balance the sheave statically has solidified it will be positively prevented from any movement relative to said member upon rotation thereof regardless of the amount of molten metal required.

7. A sheave, comprising a rim portion, a plurality of elongated pockets formed in the inner surface of said rim portion and equally spaced from each other circumferentially thereof, each of said pockets having a plurality of under-cut portions, along each of the said walls of said pockets and at each end thereof to form continuous ridges extending inwardly from the Walls of said pockets, said ridges being parallel to each other and to the inner surface of the. rim portion, said ridges being disposed between the bottom and top edges of said pockets and being spaced from said edges, a beaded lattice-work, formed on the side walls of each of the pockets and disposed at angles to said ridges, the spaces between. the ridges and the lattice-work forming holding depressions, whereby after molten metal placed ir. said pockets to balance the sheave statically has solidified it will be positively prevented from any movement relative to said member upon rotation thereof regardless of the amount of molten metal required.

PAUL V. LARSEN. 

